Spending cuts of up to $10 billion will form the centrepiece of a mini-budget to be unveilled tomorrow in an attempt to regain control of government finances hit by the rising dollar.

Usually a forecasting exercise, this year's Mid-Year Economic and Fiscal Outlook will be augmented with a series of spending cuts and program deferrals designed to ensure the budget returns to surplus in 2012-13 as forecast in May.

Prime Minister Gillard yesterday recommitted herself to the target saying the budget would be "be back in the black, back in surplus, in 2012-13 as promised".

The May budget forecast of a paper-thin 2012-13 surplus was predicated on a 90 US cent dollar. It has since climbed above $US1.01. The Reserve Bank Friday issued its own updated forecasts assuming the dollar would stay at around $US1.00 for three years.

On almost every measure to be updated Tuesday the Australian economy has performed better than expected at Budget time... The economic growth forecast of 3.25 per cent this financial year has already been upgraded by the Reserve Bank to 3.5 per cent. The forecast jobs growth of 2.25 per cent has been surpassed by annualised growth of 3.8 per cent.

High export prices are lifting our terms of trade 20 per cent, rather than the forecast 14.25 per cent.

But Treasurer Wayne Swan said the high dollar would nonetheless hurt government revenue because iron ore and coal prices were set in US dollars, meaning that Australian dollar income could fall even while international prices were rising.

In China last week he said the $10.5 billion projected revenue from the mining tax was particularly at risk.

It is understood a total of $10 billion of government revenue is in the balance over four years, easily enough to obliterate the $1 billion 2012-13 surplus projected in the budget.

Among the cuts announced Tuesday will be a delay in the "Cash for Clunkers" cleaner car rebate scheme originally promised for January 2011. It will start six months later in July 2011.

Indicating some of the decisions might be tough Ms Gillard said she had already "shown an ability to manage the Budget, to make savings, to make sure Budget dollars are doing the work we want them to do and as a result we are showing the fiscal discipline necessary to bring the Budget back to surplus."

Tuesday's statement will also acknowledge the higher dollar will save the government money in areas such as information technology and defence purchases.

As recently as last month Mr Swan dismissed Opposition calls for a pre-Christmas mini-budget as "ridiculous". Shadow Finance Minister Andrew Robb called for spending cuts to slow the dollar's rise.

The Finance Department warned in its September incoming government brief that a surplus would "be difficult to achieve" without major spending cuts.

"Even if current economic projections are met, there are pressures on the fiscal position, including on delivering a surplus in 2012-13 and beyond," it said.